After five hours of laborious scientific evidence, the Hong Kong Jockey Club inquiry into the finding of heroin in a post-race swab taken from the racehorse Cupid earlier this year has again been adjourned. Trainer David Hill sought and was granted the adjournment in order to seek out an independent, expert witness. The next sitting of the inquiry is expected to be held late next month. 'I want to call in an expert opinion,' Hill said during a break in proceedings late yesterday. 'There have been a lot of points raised today that need to be further evaluated.' The Jockey Club's executive director of racing, Winfried Engelbrecht-Bresges, said the inquiry had become 'extremely detailed', with a large volume of scientific evidence on the nature of the heroin derivative and its characteristics. 'I would expect the inquiry to resume some time in the second half of August.' Meanwhile, Macau trainer Alan Ngai has lodged an appeal against the severity of the penalty - a five-month disqualification and $300,000 fine - imposed on him by stipendiary stewards at the conclusion of a high-profile inquiry on Wednesday. Ngai pleaded guilty to having trained three recent winners which swabbed positive for prohibited substance sildenafil, a key constituent of Viagra. The Macau Jockey Club reported yesterday that Ngai contends the penalty imposed by stewards is excessive and he is seeking a hearing by the committee where he can appeal against its severity. Ngai's request for a stay of proceedings has been granted. The winners in question were Lovely (two wins, June 10 and 17) and Sudden Hope (June 15).